Heney e



(No Model.) l

' H. R. TOWNE & T. W. GAPEN.

Double Lift Hoist. Y No. 239,408. Patented March 29,1881.

www-M i lNvl-:N'TORS A 2.21 WrTNEssas 24M ygw N.PETERS,PHOTO'UTHUGRAPHER. WASHINGTON. D. C.

e UNITED 4STATES `PATENT OFFICE.

HENRY R. TOWNE AND THOMAS W. CAPEN, OF STAMFORD, CONNECTICUT, ASSIGNORSTO THE YALE LOCK MANUFACTURING COMPANY, OF SAME PLACE.

DOUBLE-LIFT HOIST.

SPECIFICATION forming part of Letters Patent No. 239,408, dated March29', 1881.

Application filed January 20, 1881. (No model.)

To all whom tt may concern:

Be it known that we, HENRY R. TOWNE and THOMAS W. CAPEN, of Stamford, inthe county of Fairfield and State of Connecticut, have in- 5 ventedcertain new and useful Improvements in Hoists, of which the following isa specification, reference being had to the accompanying drawings.

Our invention consists in certain improve- 1o ments in what are known asdouble-lift hoists,77 made under the patents of Thomas A. Weston.

The objects of our invention are the better guiding of the chain intoengagement with the pocketed chain-wheel, the stripping of the chainfrom the samewheel on the oppositeside,

andthe arrangement of the ratchet-wheels and disks so as to insureproper frictional contact and the retention of the disks in -theirproper zo axial positions.

Referring to the drawings, Figure l is atop view of the hoist; Fig. 2,an end elevation of the same; Fig. 3, a longitudinal cross-section onthe line X Y; Fig. 4, a transverse section Fig. 5, an elevation of thechain-guide and `stripper removed from the machine; Fig. 6, a top viewof the same; Fig. 7, a top view or plan `of the chainguide,'stripper,and chainwheel in their relative positions 5 and Fig. 8,

3o an end elevation of the same with the chain shown in position.

A is the main frame or housing of the machine, :which we prefer to castin one piece.

B B are two caps covering apertures in the 3 5 topof the frame orhousing.

C is the main shaft or axle, andD the'coun-` ter-shaft. On one end'ofshaft C is'the spurwheel E, gearing into the pinion F on the end of theshaft D. 0n the other end of the shaft 4o D is the rope-wheel Gr, bywhich power is communicated' to the machine in the usual manner. Ifdesired, a crank or pulley may be substituted for the rope-Wheel G.

H is `the pocketed chain wheel or sheave,

around whichpasses the chain T, as shown in Fig.- 8. This sheave haspockets formed init, `with `which the links of the chain engage, so

that the chain cannot slip within the wheel.

the lugs U. Attached to the chain-guide by the bolt S is thechain-stripper R, the upper end of which is curved to t against theinner circumference or groove of the she-ave H, as shown in Figs. 3, 5,and 8, so thatitstwo points serve to strip the chain from the sheave and`preventits clinging tothe latter. The adjacent faces of the chain-guideQ and stripper R are formed so as to leave two cruciform openings at thebottom, as shown in Fig. 6, through one or the other of which openingsthe chain must always pass in order to engage with the sheave H. rIhechain-guide'and stripper, instead of being formed of two parts, Q, andR, and bolted together, may, of conse, be formed of these two parts castin one piece.

The shaft C has cut upon it a coarse screwthread, as shown in Fig. 3.The sheave H has formed within it aoorrespondin g screw-thread, so thatmotion either of the shaft C or of the wheel H independently of oneanother tends to cause the wheel H to move longitudinally upon theshaft, as a nut moves upon its screw. The ratchet-wheels J and K arefree to turn upon the'shaft C, or the latter to turn within them, andthey are `also free to slide endwise upon the shaft. The collar M, asshown in Fig. 3, bears against a shoulder and is pinned fast to theshaft C. The collar L is screwed onto the shaft C, and afterward pinnedin the same manner as the collar M, so that it cannot unscrew. Each ofthe ratchets has two pawls, in order to diminish the amount of backmotion or play, and the teeth ofthe ratchet-wheel K turn in an oppositedirection to thos'e of the wheel J.

The action of the machine is as follows: lf we supposea load to besuspended upon the left-hand part of the chain T, (see Fig. 8,) theweight of the load will tend to rotate the chainwheel to the left, orawa-y from the eye, as the parts are seen in Fig. 3. The shaft()remaining stationary, the eifect of this rotation of the wheel H is toscrew it on the shaft to the left, and thus, by frictional contact, intoengagement with the ratchet-wheel J. The rotation of this wheel, asshown in Fig. 4, is checked by the pawls O and l?, so that it cannotrotate to the left, and the sheave H and ratchet J being securely lockedtogether, the load cannot descend. The heavier theload the greater isthe rotative pressure on the sheave H, and the greater its consequentengagement by the action of the screw on the shaft C with the ratchet J.Practically these two parts thus become one, and the pawls, engagingwith ratchet J, sustain the load. In like manner the same endwisepressure caused by the load presses the ratchet-wheel J to the leftuntil it bears against the fixed collar L, which latter is preventedfrom moving endwise by being screwed onto the shaft C and pinnedthereto,

as above described. It will thus be seen that the pull of the load,acting upon the sheave H, causes the latter to be screwed up on theshaft G, thus pressing the ratchet-wheel J against the collar L andlocking these three parts into engagement with one another. If, now, therope-wheel G be turned so as to rotate the shaft C to the right, orbackward-that is, in the direction to raise the load-the collar L, beingpinned fast to the shaft O, rotates with it, and, being also locked byfrictional contact into rigid engagement with the ratchet-wheel J,carries the latter with it, and this, in turn, rotates in the samedirection the sheave H,

which carries the chain, and thus raises the load. During this actionthe pawls O and l? slip over the teeth of the ratchet J. If the motionof hoisting be stopped, these pawls, engaging with the ratchet, hold theload suspended and prevent its descent. During this action the oppositeratchet-wheel, K, has been idle, since, the sheave H being screwed hardto the left, the ratchet K and collar M are only loosely in contact withone another, and thus the former is at liberty to remain stationarywhile the shaft C revolves within it. In order to lower the load it isnecessary to reverse the motion of the rope-wheel G, the effect of whichis to cause the shaft C to rotate to the left, or from the eye, as seenin Fig. 3. As the shaft C is prevented from moving endwise by thecollars L and M fitting between the sides of the housing A, it followsthat rotation of shaft C to the left will tend to unscrew the sheave Hfrom its engagement with the ratchet J and push it endwise toward theright. As soon as this endwise motion of the sheave H becomes sufficientto neutralize the frictional contact between it and the ratchet-wheel Jthe sheave is free to yield to the pull of the load upon the chain T,the effectof whichis to again screw up the sheave H into engagement withthe ratchet J. If the backward motion of the shaft C is continuous, itis found in practice that the load will descend with a perfectly uniformand easy action, although we know that its descent consists of aninfinite number of infinitely small engagements and disengagementsbetween the sheave H and the ratchetwheel J, the motion of the shaft Gfirst unscrewing these two parts from engagement with one another, andthe pull of the load, as soon as they are disengaged, acting toimmediatelyscrew them together again. This action, however, isimperceptible to the eye, and

apparently the load descends smoothly and continuously. As soon as thebackward motion of the rope-wheel G is discontinued the automatic actionof theload locks the sheave H, ratchet-wheel J, and collar L again intoengagement, and everything comes to rest. The machine thus constitutes asafety-hoist in which the load is at all times suspended and cannot rundown. In order to lower it, it is necessary to reverse the motion of theparts by means of the handle or its equivalent.

The double feature of the machine consists in the duplication of theloose ratchet-wheel and fixed collar on the other end of the shaft, sothat if the load be hung to the opposite side of the chain, (theright-hand side,) as shown in Fig. 8, its tendency will be to cause theengagement of the sheave H with the ratchetwheel K and fixed collar M.In this event hoisting, lowering, and the automatic suspension of theload all occur precisely as before, but in the reverse direction, and bymeans of the parts H, K, and M, instead of the parts H, J, andL.Forasingle-actingmachineonlyoneset of these parts is required.Duplicating them, however, makes the machine doubleacting and addsgreatly to its utility.

Experience has shown that there is a tendency in machines of this kindfor the chain to vbecome twisted in passing onto the chainwheel orsheave, and also for it to cling to the latter at the point where itshould properly become disengaged from it. To overcome thesedifficulties we provide a chain-guide, Q, and the stripper R, boltedtogether, as shown in Fig. 5, and attached to the under side of thehousing, as shown in Fig'. 4. The construction of these parts is such asto leave two cruciform openings, as shown in Fig. 6, through one'or theother of which the chain must pass in going onto the sheave, accordingto the direction in which the machine is being used. An opening of thisform makes it impossible for a twist to occur in the chain, as itcompels every link to follow in the path of its predecessor. It alsopermits the chain to be drawn off at an angle in any direction, and yetinsures its passing in a proper line and direction onto the sheave Hafter it has entered the chain-guide Q. The points of the chain-stripperR enter within the deep central groove of the chain-sheave, and thus, inthe event of the chain clinging to thesheave, pass with a Wedgelikeaction between the sheave and the chain and strip them apart.

Experience has shown that the durability of IOO IOS

IIO

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the machine isenhanced by the use of thin disks of metal interposedbetween the frictional surfaces of the collars and ratchetwheels and ofthe ratchet-wheels and sheave. At first these disks were made of theproper exterior diameter to fit the desired surfaces,

e and with an interior diameter or bore corre-` sponding` to thediameter of the shaft.

Difficulty in their use was experienced, however, owing to the thin diskengaging with the screw-threads of the shaft, and thus getting out ofplace. In order to remedy this difficulty, we make use of annular diskshaving large central openings, and in order to locate and retain them intheir proper positions we provide a projecting hub and overhanginglip orring upon the two adjacent parts-as for instance, between the collar Land ratchetwheel J, and again between the ratchet-wheel J and thesheaveH. The internal diameter of our annular disks is such as to just fitover the projecting hub referred to. ln this way the disks are guidedaxially, and are at all times supported so that they cannot get out ofplace. One disk is required between the sheave and ratchet and anotherbetween the ratchet and collar, and we proportion these two disks sothat the smaller one may be punched out of the larger one, thuseconomizing material.

A further feature of our invention consists in the combination, with theshaft C and its devices, ofthe parallel shaft D, the two being connectediby suitable gear-wheels. In this way we are enabled to greatly increasethe efcieucy and capacity of a machine of this class with an almostimperceptible increase in its dimensions. Our arrangement of the partsadmits of this employment of two shafts and gearing within the leastpossible space, and secures the greatest possible compactness of parts.

Having thus described our invention, what we claim as new, and desire tosecure by Letters Patent, is-

1. In combination with the screw-threaded shaft G, carrying thescrew-threaded hoisting 0r chain wheel H and spur-wheel E, the shaft D,having the driving-pinion F, the combination being substantially as andfor the purpose set forth.

2. In combination with the chain-wheel H, the chain guide and stripper,composed of parts Q, and R, united by the bolt or rivet S, or cast inone piece, .substantially as and'for the purpose set forth.

3. The improved combined chain-guide'and stripper, consisting of theseparate parts Q and R, united by the bolt or rivet S, substantially asand for the purpose set forth.

4. The combination of the chain-wheel H with one or more ratchet-wheels,J and K, the adjacent faces of said wheels being provided on one sidewith a projecting hub or center and on the other side with a projectingrim, substantially as and for the purpose set forth.

5. The combination of the ratchet-wheel K with the collar M, theadjacent surfaces being provided on theone side with the projectiughubor center and on the other with an overhanging annular face,substantially as and for the purpose set forth.

HENRY R. frowNE. Trios. w. eArEN.

Witnesses:

E. D. OGDEN, Jr., SCHUYLER MERRITT.

